Transfer box gearing problem on V8

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landowner

landowner

Pensioner Pete
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Now there seems to be some very knowlegeable and tolerant people on here so I'm going air my gearbox problem.
Firstly, my V8 is too slow, I use top gear round town. Starting off slightly downhill I use 2nd, 4th, 5th.
Alternatively 1st, 3rd, 5th.......sometimes downhill I can go 2nd, 4th, 5th.

I have an LT85 gearbox and the transfer box has a lable saying 1.41 but I think it is lying.
I have checked my speedo with Road Angel and it is 10% slow. The rev counter is pretty accurate so what speed per 1000 revs should I be getting?
I think the t/b is 1.6 but I may be wrong.
I need a t/b and maybe a gearbox so what do I need to buy when the time comes ?
Secondly, would wear in the t/b output bearings and centre diff bearings cause vibration ?
:)
 
tacr2man said:
when you say slow do you mean top speed or acceleration , is it a carb V8 (original) ?
Click to expand...

Slow as in cruising speed, best cruising speed for economy is about 40mph.
The engine is powerfull, it will waste cars from the lights if 2nd gear is used for setting off, it would pull higher gearing than it does now, it has skimmed 4.6 heads, branched manifolds etc., I think the t/box is 1.6 spec even though it has a 1.41 lable on it but I need to be sure.
2000rpm is about 35 which is very low geared to my mind and the engine is working hard at 70 mph.
I would like to cruise at 50mph at about 2000/2500 and need to choose the correct transfer box/gearbox combination.:)
 
I have a factory V8 90 but now with a 4.6 standard r380 and 1.211 transfer box. I'm in kph but I'm pulling 100 kph at about 2,200 revs and I also pull off in 2nd. What rev counter do you have as a friens thought he had a similar problem to you but his rev counter was out.

Is your v8 factory because it should have a 1.211 tbox other than military which I think have 1.6. My 110 td5 has a 1.4. If I was you and you need a new box and t box I would go for a 1.22 out of a disco and an r380 defender box. all the best
 
DubaiLandy said:
I have a factory V8 90 but now with a 4.6 standard r380 and 1.211 transfer box. I'm in kph but I'm pulling 100 kph at about 2,200 revs and I also pull off in 2nd. What rev counter do you have as a friens thought he had a similar problem to you but his rev counter was out.

Is your v8 factory because it should have a 1.211 tbox other than military which I think have 1.6. My 110 td5 has a 1.4. If I was you and you need a new box and t box I would go for a 1.22 out of a disco and an r380 defender box. all the best
Click to expand...

That sounds like what I need, any problems at speed? does she struggle to maintain say 100kph or is it a steady cruise?
I think the best thing for me is a matching pair from a disco but I've been told that the gearlever will come up between the seats with that set up, how true is that do ya think:)

rev counter about right by the way and she revs to 7500 if you let her
 
You should be able to bolt a disco x-fer box onto your current gearbox - ill be trying it in a few days ill let you know. This will mean your sticks won't change position. Please though, someone correct me if i am wrong!
 
boydy1989 said:
You should be able to bolt a disco x-fer box onto your current gearbox - ill be trying it in a few days ill let you know. This will mean your sticks won't change position. Please though, someone correct me if i am wrong!
Click to expand...
Missed a 1.22 on fleabay the other day (50quid) thought it was too high and meant for a diesel.

Please post up how you get on as I should be doing the same soon.:)
 
I don't have any probs at speed with my set up but my motor has loads a grunt - 4.6 with performance cam. Maintaining 100kph is a doddle and it pulls well from that speed - all the way off the clock in fact but its too scary then.

A 1.22 T box off a disco 1 will go straight on to the back of your LT85 in place of your current box. The LT85 is a good box but if you need to swap it then I would probably go for an R380 as it is meant to be a bit stronger - but its a different shape and you will need an r380 trany tunnel. I believe the r380 from a disco would have the lever in the wrong place so you would need an r380 from a depender but not 100% on that. All the best.
 
I have a factory V8 110 CSW it has a 1.41 trans ratio the 90 V8 had a 1.22 I find the 1.41 fine , can pull off in 2nd no probs and I have a lot of kit on mine so quite heavy all the time. It was happy at 70+ cruise even with the original 3.5 carb engine , now its 3.9i even better.
I would think your rev counters out as at those revs I would think I was in low range :D
The solid body Lt85 is the gearbox to stick with definately longer lasting than the 380 esp in hot /heavy duty use. JMHPE:)
 
tacr2man said:
I have a factory V8 110 CSW it has a 1.41 trans ratio the 90 V8 had a 1.22 I find the 1.41 fine , can pull off in 2nd no probs and I have a lot of kit on mine so quite heavy all the time. It was happy at 70+ cruise even with the original 3.5 carb engine , now its 3.9i even better.
I would think your rev counters out as at those revs I would think I was in low range :D
The solid body Lt85 is the gearbox to stick with definately longer lasting than the 380 esp in hot /heavy duty use. JMHPE:)
Click to expand...

Interesting........

Mine is the LT85 but the T/B is a mystery, the rev counter is about right and idles at 800rpm.
I calculate my T/B output at 17.5 mph per 1000 rpm which is quite low.
I can change from first gear to 5th on a downhill start, struggles a bit but it can be done, I can start off in 3rd on a downhill start and then go to 5th easily, it will pull from 20mph in 5th and is using a lot of fuel especialy on journies.
Using the calculator above my T/B is 1.6 as all the speeds + rpms match up, I'm getting more sure about this the more data I get in so looks like a 1.2 disco T/B is on the cards:)
 
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